Copyright Statement

Abstract

To date, most of the hydrodynamic interaction studies between a tug and a ship during ship assist manoeuvers have been carried out using model scale investigations. It is however difficult to establish how well results from these studies represent full scale interaction behaviour. This is further exacerbated by the lack of proven methodologies to nondimensionalise the relative distances between the two vessels, enabling the comparison of model and full scale interaction effect data, as well as between vessels of dissimilar size ratios. This study investigates a suitable correlation technique to non-dimensionalise the lateral distance between vessels of dissimilar sizes, and a scaling option for interaction effect studies. It focuses on the interaction effects on a tug operating around the forward shoulder of a tanker at different lateral distances during ship assist operations. The findings and the non-dimensioning method presented in this paper enable the interaction effects determined for a given ship-to-tug ratio to be used to predict the safe operational distances for other ship-to-tug ratios.